Zebrafish (Danio rerio) as a model to assess the effects of cocaine as a drug of abuse and its environmental implications.

Cocaine (COC) use concerns are on the increase for both authorities and civil society. Despite this, it is important to investigate COC effects or those of its main metabolite, belzoylecgonine (BE), in consolidated aquatic model organisms, such as the zebrafish (Danio rerio). This (mini) review consists in an assessment regarding toxicological studies carried out employing zebrafish (embryos, larvae or adults) exposed to COC and/or BE indexed at the SCOPUS and Web of Science databases. Ten different endpoints were analyzed in both embryos and larvae, whereas only four were analyzed in adults. Of the 23 studies, only five investigated COC and/or BE effects following an environmental approach when exposing zebrafish, while most (18 studies) analyzed COC effects under a drug of abuse approach. Cocaine exposure was noted as altering the expression of several genes, such as those linked to COC transport proteins, dopamine receptors, SP substance production, the tachykinin system, and the tyrosine hydroxylase enzyme. BE exposure resulted in more oxidative and proteomic effects than COC in embryos. Cocaine abstinence resulted in hyperactivity associated with stereotypy in adult fish, in addition to reduced responses to visual stimuli to red light and neuronal development pattern alterations. Cocaine was noted as accumulating in zebrafish eyes, possibly due to melanin binding, and causing dose-response cardiac effects in both embryos and adults. Despite the different effects addressed by our survey, we emphasize the lack of COC and BE exposure assessments in zebrafish employing an environmental point of view.

Is There Enough Knowledge to Standardize a Cannabis sativa L. Medicinal Oil Preparation with a High Content of Cannabinoids?

Introduction: Cannabis sativa L. medicinal oils are good therapeutic options due to their wide spectrum of pharmacological applications and the easy adjustment of individual doses. The lack of standardization of methodology in the preparation of medicinal oil using the Cannabis crude extract results in elevated variability of cannabinoid concentration in the final product. The elevated variability impairs the understanding of beneficial and adverse effects related to dose-response pharmacological activities. Objective: This study aimed to conduct a review on the current methods of Cannabis oil preparation present in the literature, to demonstrate the most appropriate methodologies to ensure a product with high content of cannabinoids and terpenes. Results: The decarboxylation stage is essential for the conversion of acid cannabinoids into neutral cannabinoids, which are substances with the highest bioavailability. Lower temperatures for longer periods of time instead of high temperatures in less time are highly recommended to ensure that all the acidic cannabinoids have passed through decarboxylation. For the guarantee of a high terpene content, the separate addition of essential oil to the fixed oil prepared from the crude extract should be considered. Ultrasound-assisted extraction is one of the best performing methodologies because it is cheaper than other techniques, such as supercritical fluid extraction, besides that, ultrasound extraction is effective in short extraction times and uses small amounts of solvent when compared with other techniques. Conclusion: Although the literature about the methods of preparation of Cannabis medicinal oil is scarce, it is possible to standardize an optimized, low-cost, and effective Cannabis extractive methodology from the results found in the literature; however, this will depend on new research for methodological validation.